Aminopropyltriethoxy silane in natural rubber/silica composites: Torque and vulcanization properties

Abstract

The performance of rubbers composites in engineering application depend on the compatibility between reinforcing fillers and rubbers. It is a concern especially when forming rubbers composites with much contrasting of polarities between the rubbers matrix and the reinforcing fillers. However, correct compatibilizer will settle the poor interactions. This study; natural rubber (NR)/precipitated silica (PSi) composites were compounded together with aminopropyltriethoxy silane (AS) as a compatibilizer. The AS is one type of silane coupling agents and it was compounded into the composites of NR/PSi with varied doses i.e. one to seven phr. It was found that the AS significantly affected the torque and vulcanization properties of the NR/PSi composites. The AS decreased the viscosity/minimal torque but raised the maximal torque and torque differentiation. It was also found that the AS increased the rate of vulcanization. The increases in the torque and vulcanization properties were presumably attributed to the enhancement in rubber to filler interactions originating from coupling bonds formation in the presence of AS as a compatibilizer. Besides, the AS also role as a plasticizer which increased the degree of filler dispersion of PSi. Therefore, the addition of AS had a considerable potential to compatibilize the non-polar NR and PSi filler.